B51c2166-574a-4d5b-953d-a40508a5e333 - samples
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ABSTRACT:
PROVIDER: EGAD00001006667 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Here we performed whole exome sequencing on a series of 42 Microsatellite (MSI) colorectal cancers (CRC) & 133 RNA sequencing of
101 MSI CRC and 32 Microsatellite Stable (MSS) CRC
| EGAS00001004863 | EGA
Project description:Samples were taken from colorectal cancers in surgically resected specimens in 84 colorectal cancer patients. The expression profiles were determined using Affymetrix Human Genome U133 Plus 2.0 arrays. Comparison between the sample groups allow to identify a set of discriminating genes between MSI and MSS cancers and, furthermore, to determine the distinct characteristics of proximal and distal MSI cancers. Experiment Overall Design: Eighty-four colorectal cancer patients who had undergone surgical resection of colorectal cancer were studied. To identify molecular signatures of MSI cancers, gene expression profiles were compared between MSI and MSS cancers. Next, we examined the difference in gene expression profiles between proximal and distal MSI cancers.
2008-06-13 | E-GEOD-4554 | biostudies-arrayexpress
Project description:Samples were taken from colorectal cancers in surgically resected specimens from 74 patients. The expression profiles were determined using Affymetrix Human Genome U133Plus 2.0 arrays. Our MSI/MSS classifer was applied to these samples. Experiment Overall Design: mRNA from 74 fresh-frozen primary colorectal tumour samples were extracted and hybridized to HG-U133Plus 2.0 expression arrays. The MAS5.0 procedure was used to make calls of expression. Data from each sample were quantile normalized with reference to a training set prior to application of our MSS/MSI classifier.
2009-01-16 | E-GEOD-13067 | biostudies-arrayexpress
Project description:Background. Colorectal cancer develops through two main genetic instability pathways characterized by distinct pathologic features and clinical outcome. Results. We investigated colon cancer samples (23 characterized by microsatellite stability, MSS, and 16 by high microsatellite instability, MSI-H) for genome-wide expression of microRNA (miRNA) and mRNA. Based on combined miRNA and mRNA gene expression, a molecular signature consisting of twenty seven differentially expressed genes, inclusive of 8 miRNAs, could correctly distinguish MSI-H versus MSS colon cancer samples. Among the differentially expressed miRNAs, various members of the oncogenic miR-17-92 family were significantly up-regulated in MSS cancers. The majority of protein coding genes were also up-regulated in MSS cancers. Their functional classification revealed that they were most frequently associated with cell cycle, DNA replication, recombination, repair, gastrointestinal disease and immune response. Conclusions. This is the first report that indicates the existence of differences in miRNA expression between MSS versus MSI-H colorectal cancers. In addition, the work suggests that the combination of mRNA/miRNA expression signatures may represent a general approach for improving bio-molecular classification of human cancer.
2007-09-07 | E-TABM-326 | biostudies-arrayexpress
Project description:We compared the expression of genes related to inflammatory cytotoxic functions between MSI and MSS (HLA class I negative and positive) gastrointestinal adenocarcinomas (GIACs), seeking evidence of differences in inflammatory mediators and cytotoxic T-cell responses. Twenty-two GIACs were divided into three study groups as a function of HLA class I expression and MSI phenotype. Comparison between eight high-level MSI (MSI-H) and 8 MSS/HLA+ (control) cancers identified 2170 differentially expressed genes (p< 0.05) after microarray analysis on the Affymetrix HG-U133-Plus-PM plate. We grouped genes in Gene Ontology functional categories: apoptotic programme (119 genes, p=5.1·10-7), leukocyte activation (32 genes, p=0.01), T cell activation (20 genes, p= 0.01), and cytokine production (19 genes, p= 0.04). Real-time RT-PCR and immunohistochemical evaluation were used to confirm some microarray data, finding that increased mRNA levels of pro-inflammatory cytokines and cytotoxic mediators were associated with greater infiltration by CD8+ T lymphocytes in the MSI-H group (p<0.001). Finally, tumours with immunohistochemical HLA class I negative pattern were not grouped together but rather in accordance with features of the gene expression profile of MSI or MSS tumours. As expected, genes associated with antigen processing machinery and MHC class I molecules (TAP2, B2m) were downregulated in MSS/HLA-ABC negative CRCs. In conclusion, microarray and immunohistochemical data may be useful to comprehensively assess tumour-host interactions and differentiate MSI from MSS cancers. The two types of tumours, MSI/HLA- and MSS/HLA-, showed marked differences in the composition and intensity of infiltrating leukocytes, suggesting that their immune escape strategies involve distinct pathways. Case-control study. Samples were selected according to immunological criteria: those with total loss of HLA antigens and those without alterations in the expression of HLA molecules. In addition, the microsatellite instability genotype of all the samples was also analyzed, resulting in microsatellite stability (MSS) and microsatellite instability (MSI) samples. Therefore, three groups of samples were selected: MSS/HLA+, MSS/HLA-, and MSI. The MSS/HLA+ group was used as the control.
2011-02-28 | E-GEOD-27544 | biostudies-arrayexpress
Project description:mRNA assays were performed on 51 samples of human colorectal tumors using Affymetrix HuGeneFL arrays containing 7129 probe-sets. We compared 38 microsatelite stable (MSS) tumors with 13 microsatellite instable-high (MSI) tumors to form a list of genes differing between the two types. In order to identify molecular signatures characterizing MSI tumors, we examined only MSI-high cancers and not MSI-low ones. Keywords: disease state analysis Human samples of 38 microsatellie stable and 13 microsatellite instable-high colorectal tumors, each from a separate patient, had mRNA assays performed using Affymetrix HuGeneFL arrays, with 7129 probe-sets. A supplementary Excel file (Colon_HuFL_logs.xls) is attached below that gives the log-transformed probe-set values. It also gives the p-values from T-tests comparing these values between MSS and MSI samples, as well as an estimated average fold-difference, for which the mathematical functions are explicitly given.
2009-04-10 | E-GEOD-11543 | biostudies-arrayexpress
Project description:Samples were taken from colorectal cancers in surgically resected specimens in 84 colorectal cancer patients. The expression profiles were determined using Affymetrix Human Genome U133 Plus 2.0 arrays. Comparison between the sample groups allow to identify a set of discriminating genes between MSI and MSS cancers and, furthermore, to determine the distinct characteristics of proximal and distal MSI cancers. Keywords: repeat
2006-10-17 | GSE4554 | GEO
Project description:We compared the expression of genes related to inflammatory cytotoxic functions between MSI and MSS (HLA class I negative and positive) gastrointestinal adenocarcinomas (GIACs), seeking evidence of differences in inflammatory mediators and cytotoxic T-cell responses. Twenty-two GIACs were divided into three study groups as a function of HLA class I expression and MSI phenotype. Comparison between eight high-level MSI (MSI-H) and 8 MSS/HLA+ (control) cancers identified 2170 differentially expressed genes (p< 0.05) after microarray analysis on the Affymetrix HG-U133-Plus-PM plate. We grouped genes in Gene Ontology functional categories: apoptotic programme (119 genes, p=5.1·10-7), leukocyte activation (32 genes, p=0.01), T cell activation (20 genes, p= 0.01), and cytokine production (19 genes, p= 0.04). Real-time RT-PCR and immunohistochemical evaluation were used to confirm some microarray data, finding that increased mRNA levels of pro-inflammatory cytokines and cytotoxic mediators were associated with greater infiltration by CD8+ T lymphocytes in the MSI-H group (p<0.001). Finally, tumours with immunohistochemical HLA class I negative pattern were not grouped together but rather in accordance with features of the gene expression profile of MSI or MSS tumours. As expected, genes associated with antigen processing machinery and MHC class I molecules (TAP2, B2m) were downregulated in MSS/HLA-ABC negative CRCs. In conclusion, microarray and immunohistochemical data may be useful to comprehensively assess tumour-host interactions and differentiate MSI from MSS cancers. The two types of tumours, MSI/HLA- and MSS/HLA-, showed marked differences in the composition and intensity of infiltrating leukocytes, suggesting that their immune escape strategies involve distinct pathways.
2011-02-28 | GSE27544 | GEO
Project description:mRNA assays were performed on 51 samples of human colorectal tumors using Affymetrix HuGeneFL arrays containing 7129 probe-sets. We compared 38 microsatelite stable (MSS) tumors with 13 microsatellite instable-high (MSI) tumors to form a list of genes differing between the two types. In order to identify molecular signatures characterizing MSI tumors, we examined only MSI-high cancers and not MSI-low ones. Keywords: disease state analysis
2009-04-10 | GSE11543 | GEO
Project description:Samples were taken from colorectal cancers in surgically resected specimens in 155 colorectal cancer patients. The expression profiles were determined using Affymetrix Human Genome U133Plus 2.0 arrays. Our MSI/MSS classifier was applied to these samples. Keywords: Expression profiling by array
2009-01-22 | GSE13294 | GEO